This isolates and develops the forearm extensors. If
you use one arm at a time with cables, you get constant, full-range-of- motion
resistance that doesn't change throughout the movement like dumbbells do. This
makes this exercise for overcoming week forearm extensors, especially if one arm
is bigger than the other (Don't you just hate that).

Implementation: (A) Utilizing a floor pulley, grip a
handle with one hand, and hold it palms-down. (B) Keeping your elbow still, curl
the back of your hand up as far as you can toward your delt; Once you reach the
top pause and then lower your hand again, fighting the weight all the way down.
Finish your set with one arm, then work your other arm.